<template>
  <div id="app">
    <div>
      <span>全选:</span>
      <input type="checkbox" v-model="all" />
      <button @click="fan">反选</button>
      <ul>
        <li v-for="(item, index) in list" :key="index">
          <input type="checkbox" v-model="item.checked" />
          <span>{{ item.name }}</span>
        </li>
      </ul>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      list: [
        {
          name: "猪八戒",
          checked: false,
        },
        {
          name: "孙悟空",
          checked: false,
        },
        {
          name: "唐僧",
          checked: false,
        },
        {
          name: "白龙马",
          checked: false,
        },
      ],
    };
  },
  computed: {
    all: {
      get() {
        return this.list.every((item) => item.checked);
      },
      set(val) {
        this.list.forEach((item) => (item.checked = val));
      },
    },
  },
  methods: {
    fan() {
      this.list.forEach((aa) => {
        aa.checked = !aa.checked;
      });
    },
  },
};
</script>

<style>
</style>